A boost converter or step-up converter is a DC-DC power converter that generates an output voltage that is greater in magnitude than the input voltage. In a typical application, the boost converter is one portion of a circuit solution that generates a high voltage supply, which is then used to drive an amplifier. However, such a solution requires two inductors—one for the boost converter to charge and discharge, and one for the amplifier to block the switching frequency from the capacitive load.
Further, for a capacitive load, such a piezo ceramic speaker, the load can be driven with a continuous time varying signal, such as an audio signal.
Thus, it would be desirable to provide a boost converter for capacitive loads that has a compact design that does not require two inductors, while still providing acceptable fidelity and high efficacy.